/*
 * Copyright (c) 2020, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 * WSO2 Inc. licenses this file to you under the Apache License,
 * Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.wso2.carbon.apimgt.keymgt;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.wso2.carbon.apimgt.keymgt.model.SubscriptionDataStore;
import org.wso2.carbon.apimgt.keymgt.model.impl.SubscriptionDataStoreImpl;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/*
 * This class holds tenant wise subscription data stores
 * */
public class SubscriptionDataHolder {

    protected Map<String, SubscriptionDataStore> subscriptionStore =
            new ConcurrentHashMap<>();
    private static final Log log = LogFactory.getLog(SubscriptionDataHolder.class);
    private static SubscriptionDataHolder instance = new SubscriptionDataHolder();

    public static SubscriptionDataHolder getInstance() {

        return instance;
    }

    public SubscriptionDataStore registerTenantSubscriptionStore(String tenantDomain) {

        SubscriptionDataStore tenantStore = subscriptionStore.get(tenantDomain);
        if (tenantStore == null) {
            tenantStore = new SubscriptionDataStoreImpl(tenantDomain);
        }
        subscriptionStore.put(tenantDomain, tenantStore);
        return tenantStore;
    }

    public void initializeSubscriptionStore(String tenantDomain) {

        SubscriptionDataStore tenantStore = subscriptionStore.get(tenantDomain);
        if (tenantStore != null) {
            tenantStore.init();
        }
    }

    public void unregisterTenantSubscriptionStore(String tenantDomain) {

        SubscriptionDataStore subscriptionDataStore = subscriptionStore.get(tenantDomain);
        if (subscriptionDataStore!= null){
            subscriptionDataStore.destroy();
        }
        subscriptionStore.remove(tenantDomain);
    }

    public SubscriptionDataStore getTenantSubscriptionStore(String tenantDomain) {
        if (subscriptionStore != null && tenantDomain != null) {
            SubscriptionDataStore subscriptionDataStore = subscriptionStore.get(tenantDomain);
            if (subscriptionDataStore == null) {
                synchronized (tenantDomain.concat("getTenantSubscriptionStore").intern()) {
                    subscriptionDataStore = subscriptionStore.get(tenantDomain);
                    if (subscriptionDataStore == null) {
                        subscriptionDataStore = registerTenantSubscriptionStore(tenantDomain);
                    }
                }
            }
            return subscriptionDataStore;
        }
        return null;
    }

    public void refreshSubscriptionStore() {
        subscriptionStore.keySet().forEach(tenant -> {
            // Cleaning the existing SubscriptionDataStore instance before re-population
            subscriptionStore.put(tenant, new SubscriptionDataStoreImpl(tenant));
            if (log.isDebugEnabled()) {
                log.debug("Refreshing subscription data store for tenant: " + tenant);
            }
            initializeSubscriptionStore(tenant);
        });
    }

}
